How can I create and access multiple databases in Oracle 11g? - database

I have bought a Oracle 11g recently and I wanted all my developers to use it. Obviously I can't buy different licenses for each. So is it possible for me to create one database for each of the developers?. By inference I know it is possible.
However, I couldn't find how I can do it. I googled. There was no definite guide for this particular case. Can you point to the right resource?
Or could you list down the steps to achieve this?
I would ever be grateful.
-
Sheldon

When you create a user in Oracle, you're creating a schema. A schema is a collection of tables and related objects (views, functions, stored procedures, etc) specific to that schema. So each developer could have their own user/schema, and work independently of one another. Access to other users can be granted, and public synonyms can be created to ensure that YOUR_TABLE points to a YOUR_TABLE in a specific schema, without the need to specify that schema. But this can eat space...
If there is shared development, might be best to have a single schema so everyone is working on the same copy.

Create one database and give each developer it's own schema (username/password).

As long as all your database instances are on the same server you can build as many as you want without paying any more. Performance might become an issue with more instances depending on how heavily used they are.
You don't mention your platform.
On windows, here's how to use the Database Configuration Assistant (DBCA). I think it's pretty similar on *nix as well.
Each database so created has a different name. To access them it's simply a matter of using a tnsnames.ora file with different entries for each instance on the server.

You can buy Oracle personal edition for each developer and install it on their desktop/laptop. According to shop.oracle.com it's $460 per user. This way you can give everyone full access to Oracle and save a lot of trouble. Developers can learn Oracle more quickly and be more productive, and DBAs won't have to worry about them bringing down the server.
Or possibly you could even use it for free if your program is not in production yet. The Oracle Developer license lets you:
... use the Programs, subject to the restrictions stated in this
Agreement, only for the purpose of developing, testing, prototyping,
and demonstrating Your application and only as long as Your
application has not been used for any data processing, business,
commercial, or production purposes, and not for any other purpose.

Related

Copy dbo to a new Schema in MSSQL

I got a database in SQL where everything is in the dbo schema. Now we want to copy that schema to have two schemas in the same database with the exact same content. Is there any easy way to do this in an Azure Database?
(We want to separate our Development and UAT but still only use one database)
While the other answer posted here, using the SSIS to transfer the SQL objects, will work, I feel compelled to point out that your approach raises a lot of other concerns.
Using a single database for two environments is not a good practice. The first big issue with is how do you handle deployments? Let's say UAT is in the uat schema and development is in development is the dev schema. You make a change to the Customers table, how do you deploy the table change to both schemas? If you use SSIS, you will need an on-premise SSIS server that handles copying the changes to the various shcemas in the target database. This will create a large maintenance headache and likely lead to important changes being wiped out.
Another issue this results in how does your application target a specific schema? You can have a login defaulted to a specific schema when it runs, but many ORM tools will want to the schema ahead of time. This will force to write the code in way that could potentially force to deploy different code to different environments. This opens up the possibility that parts of the code won't get test until production.
The last concern I have is with this approach, versioning your database becomes difficult and many of the tools that are out there, won't support what you are doing. This means you will likely be creating custom processes and tools to deploy a database instead of leveraging tools built by vendors like Microsoft or Red Gate. This puts you in a position where you need to support not only the application you make for your customers, but also an application to do your job (basically doubling your work).
My suggestion is think about the need to run two environments in a single database. I'm assuming this is likely due to cost, in which case you might find this to be false. Azure has many pricing tiers to support customers with various budgets. Depending on your application workload for both environments, you will likely find you need a large DTU database to support both. You might find that by having two databases, you can leverage smaller DTUs tiers which may end up being cheaper.
Please use the CopySchema option of the Transfer SQL Server Objects Task in SSIS as explained here.

How to amalgamate client databases into one database?

In my company we have a selected list of companies that are using our in-house built tool (e.g. Northwind).
When we make changes we deploy these to all our client locations.
The structure currently is: the application is installed at the client's location and the databases sit with them.
However, we would like to consolidate all this information into one database and clients will connect via web services for any data requests.
For example....We have deployed Northwind App and Db to company X, Y and Z and would like to create a single database to maintain all these company's data.
We have reviewed one option which is to create a field for the Company to associate it with the various tables and another option is to create a schema for each company and in this way we can allocate permissions to the relevant company. Is there an alternative to this and what are the pros and cons to the ways we could do this.
One con with adding a company field, is that we have to cater for indexes being the same in all the client databases and this makes it more difficult and the performance of the app as a whole due to multiple requests to the same db. Please Help?
Note: Using Sql Server 2008
Research "multi-tenant database architecture". (For your purposes, think of one tenant as one client.) You'll find a spectrum from "one database per tenant" to "every tenant in every table".
Read carefully. Writers in this field can confuse you. Expect technical terms like shared schema to mean different things to different writers.
See this SO answer for tradeoffs.
For your first step, I wouldn't consider anything besides simply moving those client databases in-house. Just doing that is going to give you and your application programmers enough headaches. You don't need an architectural change on top of it.
That will also give you time for research and testing.

Choosing database and licensing for Delphi application

We have Delphi XE2. We are looking for a database for our application. We have tried Absolute Database and it supports most of SQL commands we need. I see most of Delphi users choose Firebird but it seems to hard to work with. I am so much confused about databases and licenses. Here are my problems:
When we choose a database, let's say Absolute Database, Firebird, MySql embedded etc. and if we have for example 3.000 customers, do we still need to pay to Database developers? Or is it one time fee? I am so much confused because they say when we buy, we can use it inside our building ( http://www.componentace.com/order/licenses.php ). But when we release our software, our customers will need to use the same database of course.
Absolute DB is easy to install and supports most of SQL queries. Firebird does not support most of SQL queries. Is this correct?
When we try to use Firebird, we use FlameRobin to design database. But when we try to connect using IB components, it says "Unable to connect database".
Thank you very much...
Firebird has no licensing fees at all. However, it's smart to help maintain this great project once you rely on it. There is a lot of ways to help Firebird project:
http://www.firebirdsql.org/#consider-your-contribution
Not correct. Firebird is very powerful and supports most SQL standards plus a great SQL extensions for stored procedures and triggers
Check your database connection string. It's usually something like server_ip:full_db_path if you're connecting over a network, or just full_db_path if local. You can always use an ALIAS in place of full_db_path. Make sure you have Firebird server running or, if using embedded, if it's installed correctly. Firebird has a great and very complete documentation and one of the best support groups on open source projects.
It depends on database. Absolute Database is embedded database, everything is included in your exe. Most database engines however are standalone, so they are installed as applications. It looks like if you buy commercial Absolute Database licence, no royalties are needed: http://www.componentace.com/order/order_product.php?id=8
Firebird supports most SQL standards. According to this answer, most SQL compliant embedded database is Firebird: Which embedded database has maximum SQL compliance, and concurrency support?
You must have some configuration issues with IB components, hard to say more without more information. On the otherhand, IB components are for Interbase, so you might find something else better, like UIB.
If you'll choose Firebird, then take a look at IBExpert. This is absolutely the best administration tool available for Firebird. But not cheap. =(
You should also look at Interbase, also marketed by Embarcadero, the Delphi vendor. Interbase is not the same thing as Firebird, which is probably why the IB components you mentioned didn't work.
Yes, each customer will usually have to purchase the IB database. However, there are additional choices with Interbase, depending on how you structure your application. Check how they work and see if they can fit better with what you are trying to do.

Sub version for database (I want something for data values in the database, not for the schema)

I am using github for maintaining versions and code synchronization.
We are team of two and we are located at different places.
How can we make sure that our databases are synchronized.
Update:--
I am rails developer. But these days i m working on drupal projects (where database is the center of variations). So i want to make sure that team must have a synchronized database. Also the values in various tables.
I need something which keep our data values synchronized.
Centralized database is a good solution. But things get disturbed when someone works offline
if you use visual studio then you can script your database tables, views, stored procedures and functions as .sql files from a database solution and then check those into version control as well - its what i currently do at my workplace
In you dont use visual studio then you can still script your sql as .sql files [but with more work] and then version control them as necessary
Have a look at Red Gate SQL Source Control - http://www.red-gate.com/products/SQL_Source_Control/
To be honest I've never used it, but their other software is fantastic. And if all you want to do is keep the DB schema in sync (rather than full source control) then I have used their SQL Compare product very succesfully in the past.
(ps. I don't work for them!)
You can use Sql Source Control together with Sql Data Compare to source control both: schema and data. Here is an article from redgate: Source controlling data.
These are some of the possibilities.
Using the same database. Set-up a central database where everybody can connect to. This way you are sure everybody uses the same database all the time.
After every change, export the database and commit it to the VCS. This option requires discipline and manual labor.
Use some kind of other definition of the schema. For example, Doctrine for php has the ability to build the database from a yaml definition which can be stored in the vcs. This can be easier automated then point 2.
Use some other software/script which updates the database.
I feel your pain. I had terrible trouble getting SQL Server to play nice with SVN. In the end I opted for a shared database solution. Every day I run an extensive script to backup all our schema definitions (specifically stored procedures) for version control into text files. Due to the limited number of changes this works well.
I now use this technique for our major project and personal projects too. The only negative is that it relies on being connected all the time. The other answers suggest that full database versioning is very time consuming and I tend to agree. For "live" upgrades we use the Red Gate tools, they do both schema and data compare and it works very well.
http://www.red-gate.com/products/SQL_Data_Compare/. We were using this tool for keeping databases in sync in our company. Later we had some specific demands so we had to write our own code for synchronization. Depends how complex is you database and how much changes is happening. It is much simpler if you have time when no one is working and you can lock database for syncronization.
Check out OffScale DataGrove.
This product tracks changes to the entire DB - schema and data. You can tag versions in any point in time, and return to older states of the DB with a simple command. It also allows you to create virtual, separate, copies of the same database so each team member can have his own separate DB. All the virtual copies are tracked into the same repository so it's super-easy to revert your DB to someone else's version (you simply check-out their version, just like you do with your source control). This means all your DBs can always be synchronized.
Regarding a centralized DB - just like you don't want to work on the same source code, you don't want to be working on the same DB. It means you'll constantly break each other's code and builds each time someone changes something in the DB.
I suggest that you go with a separate DB for each developer, and sync them using DataGrove.
Disclaimer - I work at OffScale :-)
Try Wizardby. This is my personal project, but I've used it in my several previous jobs with great deal of success.
Basically, it's a tool which lets you specify all changes to your database schema in a database-independent manner and then apply these changes to all your databases.

How do you put an large existing database (schema) under source control?

My DBA just lost some development work that he did on our development database. Poor fella. So naturally our manager asked him, at our status meeting, how this could happen and how we could avoid this happening in the future. "Source control could alleviate the problem" I suggested... The dba's response; "No, we just backup the server more often". Now I would like to help my DBA understand what source control is and how it fits together with a database schema and development on that schema.
Previously I've tried to explain him that there's nothing special about the source code behind tables and stored procedures and it should be in a source control system (TFS in this case). But he just didn't bite. Now, while this misap is in recent memory, I would like to take another stab at it.
So my question is, do you know of any good advice I could pass on to my DBA and maybe even a couple of resources explaining how you would go about migrating a DB schema to be under source control and find its proper place in the build and deployment processes?
A couple of facts about the environment:
Source Control on a TFS 2008 Server.
Database is a MS SQL server 2008 with >300 tables and >300 other objects (sprocs, triggers, functions etc.).
Clarification:
We have been using DB Ghost and other change management solutions on other projects with other DBAs, in the past. We even have the license for VS DB edition! The problem is getting the DBA to even think about this way of developing for the database. He's really old school (i.e. migrating changes manually from environment to environment), and unfortunately hes the only one who knows anything about this particular DB.
See how to version control sql server databases and Do you source control your databases, among many others. Or use the search page. Basically, your approach seems correct. Good luck persuading the DBA...
If you are using Visual Studio Team System, I recommend having a stab at their Database Edition (i think these days it comes with the Developer Edition if you are an MSDN Subscriber). What this will allow you to do is to script out all your schema, stored procs, views, triggers, etc and source control these. This should also make the dba more comfortable since he will be working with a "Database" version of the tool rather than the "Developer" version (naming can go a great lengths with people). As you make changes from Visual Studio, you can manage script changes as you work, and source control them.
If your company has an MSDN license, they can use the Visual Studio Database edition. There's a video tutorial of it here.
I have no power of purchase, so I don't know what the cost breakdowns are. But it has the capability of source controlling all the parts of a DB schema, and includes creating change-scripts as well as auto-deploying straight from VS if you want (I wouldn't recommend that).
In general though, it's pretty solid as a database source control option.
Source control for databases can be quite contentious. It's different to use source control for something that produces a binary because you can't lock the source: a stored proc is a row in a table and there is not single table to read to get a table definition.
Also, version to version is mostly a set of ALTER statements. You script out CREATEs and add them to source control. This makes it harder to use in cases like this.
To me, this is more a procedural error.
Why was the change not done from a script? Forget where the script lives, but why no reproducable and re-runnable script? Perhaps linked to the change tracking number? If the database is reset (loaded from prod) then how would the change have been re-applied to prepare for production. And other questions.
I believe in source control and we use it: but it has limits for database work.
First you are approaching this incorrectly. If the dba won't bite on Source Control and he is making errors that affect the system, the person you need to persuade is his boss.
If it helps, I'm from the old school too and I love having our database objects in source control. How nice to be able to revert one table without having to restore the whole database backup to a different location and then move the table. How much faster and simpler. How nice to be able to compare two different versions and see what changed. How nice to deploy a change and know exactly which database changes (say, for instance only twelve of the 23 possible ones) go with the part you are deploying and not some other unfinished project. How nice to know exactly which scripts were involved in a particular change you had to rollback. How nice that nobody is making on-the-fly changes on production since we now require all production changes to be from source control scripts. There are so many fewer errors and issues to worry about.
Yes it was a change in how we did business, but we did it through a policy change from on high so three was no argument and the dbas went through a couple of times and reverted any objects different from source control to the source control version, so now nobody will even think of doing a database change without it being in source control.
As the product manager for SQL Compare I've spoken to many 'traditional' DBAs who are uncomfortable with third party tools mainly because they have a system that works for them and sometimes changing can be difficult. There are many situations where I am convinced that they would benefit from our tools if only they gave them a chance. Frustrating.
One thing you might consider trying is Red Gate's upcoming tool, SQL Source Control. This is designed to build source control into SSMS, in other words it doesn't require DBAs to leave the comfort zone of their management environment. The bad news is that the tool hasn't been released yet. The good news is that we have an Early Access Program. Please visit the following link to find out more about the tool:
http://www.red-gate.com/Products/SQL_Source_Control/index.htm
you can't really put a large database under source control, so your DBA is right.
what you can do practically is to put your schema under source control, and maybe a few smallish 'configuration' tables.
One way to source control database is to store the data in and about the database separately
You can have the all the tables, procedures and function scripts as SQL files and add them to source control.
Export the database data as insert statements into SQL files, each with a fixed size. This is a cumbersome process as it would involve a lot of files that are to be tracked and controlled.
I am not sure if the VSS/SVN are able to read and keep history of changes to dump files created by the database backup options.
Its not clear from you question if you want to protect the data in the Db or the schemas in the Db. If the latter then you could identify all the important schemas and run an cron job that pulls the schema definitions from the Db and inserts them automatically into a source control system (perhaps even via triggers on the schemas??).
But this still just amounts to backing the system up more often. For what you envision you would need source control integrated with the Db tools and I don't know of any product that does that.
(and I shudder to think of VSS integrated into SQL management studio :-(( )
My answer to this same problem was to export all DB objects to text form (more than 136,000 of them) and then create the SourceSafe projects to hold them. Any New or changed objects in the DB now go to the SourceSafe structure, while unchanged are left alone.

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